Polymers designed with high dielectric constants, low dissipation factors and high electric field breakdown strengths have application as dielectrics in capacitors for communication equipment, computers, and space power systems. Charge storage in polymer film capacitors are controlled by the dielectric properties such as dielectric constant, dielectric loss, and breakdown strengths of the films employed. For example, poly-vinylidene fluoride (PVDF) and its derivatives and copolymers are known to exhibit the highest dielectric permittivity for commercially available polymeric materials and are quickly becoming useful for a number of applications. PVDF is readily formed as thin sheets and has other good dielectric properties such as high voltage breakdown strengths and low dielectric losses.
There have been numerous studies aimed at increasing the dielectric constant of PVDF films. One study attempted to increase the dielectric constant of PVDF films by forming a composite of PVDF and a high dielectric constant inorganic material such as lead zirconate titanate. The problems with such procedures are that the required percentages of added inorganic material is necessarily large, that is, greater than 20 percent, and overall desirable properties of PVDF film becomes altered. Resulting composite films are also extremely brittle and therefore unprocessable and also have low dielectric breakdown strengths making them unsuitable as dielectrics for wound capacitor applications.